(and editing drivers/char/tty_io.c to get the kernel to compile) solved the problem for me. st.c is using the name put into kobj.name in making the class file names. I will make a patch that removes this dependency.

While looking at this problem, I noticed that the naming changes already committed to BK had disappeared. Looking at st.c history revealed that the following change had been committed (sorry for wrapping) by greg@kroah.com 46 hours ago: